Network interface units (NIUs) are well known in the telephone industry as the interface between the telephone service provider and each subscriber. An example of such an NIU is shown in FIG. 1 in U.S. Pat. No. 4,979,209. This enclosure is typically installed at the subscriber location and serves as a demarcation point between the subscriber premise wiring and the telephone company line. The NIU provides a subscriber section which is accessible to the subscriber and a service provider section which is restricted from access by the subscriber. The service provider section typically contains the main telephone lines coming from the central office of the telephone service provider.
A network interface module (NIM) is placed in the subscriber section and is typically connected to the service provider section through a pair of wires which cross the sections and terminate within the subscriber section. The NIM serves to assist a subscriber in determining whether a fault exists on the incoming telephone company wiring or the subscriber premise wiring as is well known in the industry. An example of such a module is shown in FIGS. 1, 2, and 3. The NIM 10 snaps into a latching feature 16 of the NIU enclosure to secure the module into the NIU. Electrical connection to the telephone service provider line is accomplished through a pair of wires 12. A second pair of wires 18 is connected to the subscriber's telephone within the premise. As is shown in FIG. 3, the pair 12 is draped over a divider 20 which is typically placed between the subscriber section and the service provider section of the enclosure. The pair 12 is then connected to posts inside the service provider section.
The industry is currently moving towards a multiservice NIU which will be capable of providing several services such as telephony, high speed data, interactive services, and cable TV. An example of this multiservice NIU is disclosed by Motorola on their internet web site http://www.mot.com/multimedia/prod/specs/avnit.htm) as a Cable Access Unit. Such units will have a similar arrangement in that a subscriber section will be provided along with a service provider section. However, the service provider section will contain electronics for separating multiple services which are coming into the unit on a single cable into a plurality of discrete services such as cable TV, telephony, etc. to be supplied to the subscriber premise on separate circuits.
A problem exists in that the units described above require a wire to pass between the accessible and inaccessible portions of the NIU. This requires a multistep operation for installation of module. For example the module must first be mechanically secured to the unit and then be electrically connected in another step.
Another problem exists with these multiservice NIUs in that the service provider must install each of the network interface modules because the termination point at terminals 22 is inside the service provider section which is not accessible to the subscriber. It is therefore desirable to give the subscriber the ability to change modules by simply accessing the subscriber section. It is also desirable to be provide a module capable of being secured and electrically connected to the unit in a single step.